Sex is the identity given to any person at the time of birth naturally while gender is propagated by the society to the people.

Sex is attached by birth while gender is given by the society based on the work to the people.

Just like Shahid Jamal wrote sex is biological, while gender is sociocultural.

Let me elaborate a little bit.

"Gender", as it is generally used in various studies, comes down to society and how various cultural norms function in defining a person's social practice and the social group which is "attached" to that person. "To be" is an ontological term, meaning it defines a type of "belonging" to a category of knowledge and science, and, broadly speaking, "gender" defines various categories of social participation and belonging. Within Gender Studies it also touches upon how language functions in designating what is out there in the world (i.e. nature) in relation to the human social praxis of defining the "self" of a person within his/her social interrelations (i.e. culture). In this very rich in connotations term - "gender" - we can find all kinds of sociocultural ideological formations which serve to define and thus check a person's sociocultural self-image to a couple or more related terms and, thus, his/her position and role-expectations within that society: the effects can also be analysed in terms of behaviour, codes of communication, clothing, subcultures, various preferences, etc. A truism in linguistics is that there is no "natural" relation between the signifier (the word/sign "woman" or "man") and the signified (our concept of a woman or a man) thus adding up to a kind of leeway when it comes to interpretation and ultimately - definition. Language is seen as a self-enclosed signification system which sometimes misses the mark in defining a person's "gender", hence the multiple types, meanings, and implications of the word "gender" in Western European and American sociocultural discourses. It is the critical desire to escape epistemological and psychological repression when it comes to your all-too-human self-identificational drive and linguistic mechanisms that inform the economics of what a given society and its academic institutions mean by gender.

Sex and gender can be intimately related when the flow of desire and libido in general terms are addressed: various kinds of objects are produced (cultural, ideological, material, digital, etc.) and, naturally, they induce attraction or repulsion (often concurrently). Defining a person based on his/her biological sex delineates a standard of social/subcultural acceptance and recognition (or rejection for that matter) and a way to channel desire on a dichotomous scale: on the one end, for instance, being the "gender: male" kind, and on the other one - "gender: female" thus establishing a paradigm of all expectations and perceptions these words bring to mind within a specific culture. Defining a person based on his/her gender (social, cultural) identifies multiple points of relation and flow of desire between different (animate and inanimate, social and material) objects thus subjecting the conceptual elements and mechanisms of the scale previously mentioned under interrogation. More or less it is the constant production of material goods and psychological necessities (i.e. desires) which pluralise how a person can enter into relation with new objects in the world and how a person comes to see his or her "self" (as a social mirror image). So, more or less, it is the intimate relation between material conditions and the sociocultural environment which produces a gender and channels its desires by defining its ontological categorisations.

It is a difficult concept to define since the term has undergone a lot of social changes and inflections: revolutions, dissatisfaction, repression, stigmatisation, championing, eschewal, etc. Unfortunately, both terms "sex" and "gender" have been misused, misappropriated, misguided, in many different circumstances and countries where the social structures have difficulty, for one reason or another, in appropriating a new concept that would alter how people view themselves, life, and also how people relate and communicate with one another. If defining "gender" were a little bit more straightforward, then maybe it would be easier to grasp intellectually and the term would not be so ambiguous and hence fraught with social tension. But generally speaking in a lot of languages other than English the term "gender" cannot be translated adequately and various pejorative definitions of the term have been attached to it thus distorting and undermining the whole conceptual framework it brings to mind – its ideological history and all people who see themselves related to it in one way or another. It really is problematic since the emotional response to the word “gender” and all that it implies is really powerful and sometimes beyond negotiation.

Hope this was a valuable input to your question!

Dear Kiril, What a wonderful explanation have you sent me! I really appreciate your concern for my question which others might think to be unimportant.

Thank you once again

Gender is largely a social construct, which earlier relied heavily on the traditional ideas of sex.

The latter is biological and mainly refers to either male or female. This depends on the sexual organs that a person has. However, we now have the term 'Intersex' for infants born with ambiguous genitals. They may later assign a particular gender depending on the gender makeup of the child. Some people remain 'non-binary' throughout. See this news article for some interesting insights: https://www.theguardian.com/world/2016/jul/02/male-and-female-what-is-it-like-to-be-intersex

Gender as a social construct was also traditionally masculine or feminine, but now most societies are open to the non-binary aspects of gender- basically the LGBTQ and many other spectrums. Gender would ideally be a choice, whereas sex is something that is developed at birth, biologically.

Transgender individuals however go through surgical processes to 'appear' feminine or masculine, albeit not with the male/female reproductive sex organs.

The concepts of gender and sex are both in flux in the modern age, I'd say. It's very interesting that you asked this question!

Este tema é espinhoso poque termina numa necessidade de RE-EDUCAÇÃO da maioria da sociedade que nem sabe das diferenças entre sexo e gênero

Sex is the biological structure of humane beings whetehr born as male or female, but gender refers to the role attributed to sex. The way we behave, act, think has to do with gender

Sex is biologically/medically determined based on one dominant genetic predisposition whereas gender is socially constructed. this social construction of gender to a large extent facilitates and maintains societal sanctioning mechanisms used in guiding the performance of one's sex/sexuality. In my opinion, the interchangeability of both concepts in research should be done cautiously since such negligence tends to suggest, empower and justify societal gender norms detrimental to women's disadvantage. Particularly, in collectivist societies where there is strict adherence to the performance of maleness and/or womanness, insights generated using gender instead of sex may validate gender norms while reducing critical teasing of how specific aspects of gender norms influence diverse issues negatively or positively.

I recommend this interesting piece for deeper understanding: West, Candace, and Don H. Zimmerman. "Doing gender." Gender & society 1, no. 2 (1987): 125-151.

The problem is that the term "sex change" has been coined as more catchy a phrase than "gender change". We cannot change our sex which is determined at birth by reproductive anatomy, hormones etc. (Intersex babies are an exception - usually their genitalia are feminised.) But gender is defined by society and some people do not identify with what their culture considers to be masculine or feminine. But the fact is that we are unique individuals - very different to each other. So we cannot possibly be categorised by gender stereotypes. Having genital surgery changes nothing. But a person may feel more comfortable wearing the clothes of the opposite sex & presenting themselves as the opposite sex. This does not change their sex. So genital mutilation is not necessary. People will look back in future and see the terrible things that we do to our bodies to make political statements. But people use piercings and tattoos for the same purpose. I prefer to cherish my body and keep it as I was given it.